Self-powered RFID tag activated by a fluid

Abstract

RFID tag and a system and method involving a plurality of RFID tags. Each RFID tag is attached to an object on which the presence of a predefined fluid is monitored. In a first state, (absence of the monitored fluid), the tag acts as a passive RFID tag, and the information it holds can be read with a proximity reader. This operation is performed when the RFID tag is attached to the object to be monitored. In a second state, whenever the monitored fluid appears on the tagged object, a fluid activated battery generates the electrical power which is used to power the RFID tag. The RFID tag then acts as an active RFID tag and starts to emit messages which can be received by a RFID reader.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation application of co-pending patent application Ser. No. 12 / 443,722, filed on Mar. 31, 2009, which is incorporated herein by reference in its entirety.TECHNICAL FIELD[0002]The present invention relates to Radio Frequency Identifier (RFID) tags and more particularly to a passive fluid activated RFID tag that becomes active when it detects a predefined fluid.RELATED ART[0003]The problem is to monitor the presence of a fluid at one or several different places and to report this information to a distant central site. Many documents of the prior art relate to the detection of the presence of fluid using sensors. Other documents describe the use of passive or active RFID tags on objects to collect information by means of RFID readers. The problem is to find a system:[0004]capable of detecting a fluid on an object or person in one or different places;[0005]capable of sending this information and other data to a di...

AI Technical Summary

Benefits of technology

"The present invention provides a RFID tag that can act as a passive tag or a self-powered active tag in the presence of a fluid. The tag can be used to monitor multiple objects or individuals located at different locations. The invention allows for remote monitoring of RFID tags and the identification and location of tagged objects. The technical effects of the invention include improved monitoring of fluid presence and improved location tracking of tagged objects."

Problems solved by technology

The problem is to monitor the presence of a fluid at one or several different places and to report this information to a distant central site.

The problem is to find a system:capable of detecting a fluid on an object or person in one or different places;capable of sending this information and other data to a distant site;permanently easily identifiable;autonomous in terms of energy;easy to build;cheap enough to be disposable.

The wet detector is just providing information to the system, but does not provide any power to the tag that only operates as a passive tag (short distance reading).

U.S. Pat. No. 5,959,535, does not use an RFID system and therefore, cannot provide means to read the stored data as long as the battery is not in operation.

Moreover, adding an FM modulator is expensive.

This detection device or liquid sensor is not based on the RFID technology and cannot transmit in a wireless way to a remote system data (for instance the position) related to tagged objects.

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